Image button click event in datalist not firing

Image button click event in datalist not firing

I have an imagebutton which is in a datalist. Onclick, the event for the
image button is not firing. How can I get it to fire?
<asp:DataList ID="datalistsoru" runat="server"
BorderColor="#CCCCCC" BorderStyle="Solid" BorderWidth="1px" >
<ItemTemplate>
<asp:ImageButton ID="ImageButton1" runat="server"
OnClick="ImageButton1_Click" ImageUrl="~/resimler/yukariok.jpg"
ToolTip="Oyu Arttýr" />
</ItemTemplate>
protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
{
Response.Redirect("Default.aspx");
}